Makindo Medical Notes

Multisystem inflammatory disease caused by the spirochaete Borrelia burgdorferi.

About

• Lyme disease is a multisystem disease
• Caused by the spirochete Borrelia burgdorferi.
• Spread by the tick Ixodes immitis which bites man
• The tick is usually found on deer
• Ixodid ticks can be spread by birds
• Vector: deer tick (Ixodes scapularis (=I. dammini), I. pacificus, I. ricinus (Europe), I. persulcatus (Asia))
• Diagnosis based on clinical findings + endemic area as serology can be negative

Infectious agents

• Borrelia burgdorferi sensu lato - classically
• Borrelia afzelli (Europe)
• Borellia garinii (Europe)
• Endemic to USA, Asia, Europe

Seasonality

• Commoner in spring and summer months
• Usually seen in wooded areas

Clinical

Bannwarth's syndrome

• Painful radiculitis
• Peripheral motor deficits
• Lymphocytic cerebrospinal fluid (CSF).
• Patients usually have facial palsy
• Multiple cranial neuropathies, radiculopathy
• Meningoencephalitis.

Investigations

• Anti-Borrelia antibody detection is frequently negative in the early stages, but 90–100% sensitive in late disease. IgM or rising titres suggest a recent infection. There is a common issue of false positives and IgM may be normal when neurology or other symptoms come to light. A positive IgG is not always a sign of active infection. False positives - Rheumatoid disease, Infectious mononucleosis, syphilis, SLE.
• PCR testing on CSF, joint fluid, skin biopsies
• CSF: Increased Lymphocytes and protein. PCR on CSF may be useful especially with a diagnosis of neuroborreliosis
• MRI Brain: T2 Weighted MRI - can show areas of high signal and there is a predilection for frontal and parietal lobes white matter disease

Prevention

• The earlier the tick removed the less the chance of infection usually within 24 hrs
• Cover exposed skin and use insect/tick repellents
• Seeking early medical help - ticks in skin folds, back of knees. Gently pull tick away with tweezers and then disinfect
• Vaccination is now possible and commercially available
• Risk of transmission may be managed with a single dose of Doxycycline 200 mg PO

Management

• Treat based on clinical symptoms and endemic area - serology takes time to become positive. Consider Doxycycline 100 mg BD for 14 days in non-pregnant adults
• Amoxicillin in pregnant adults and children. Azithromycin is an alternative.
• Early disease - oral Amoxicillin 500 mg tds, Doxycycline 200 mg od [avoid in pregnant or children] or Cefuroxime 500 mg bd or Erythromycin 250 mg qds for 14 days (some quote 21 days)
• Disseminated disease - Doxycycline or Amoxicillin plus Probenecid for 30 days
• Neuroborreliosis - IV Ceftriaxone or IV Benzyl Penicillin for 30 days
• Patients at risk of Jarisch-Herxheimer reaction to treatment
• Heart Block: Pacemaker rarely needed, improves with antibiotics. Avoid Azithromycin. If carditis consider IV Ceftriaxone
• Isolated VII nerve palsy with normal CSF can receive Doxycycline and Amoxicillin for 2-4 weeks